Told thee.

#8 Not you, "them". As in "they" (but not the gender "they").

I think they are saying because 4=1+1+1+1 and 2+2 and 2+1+1, you only have to look for primes in it's greatest common divisor, like 2?

I'm going to find this paper. A lot of times math like this goes beyond my pay grade but it's still fun to try to understand.

That should read "a != 0, b != 0". gcd means greatest common divisor.

Huh. Let a, b and c be integers with a0 and b0, and let d=gcd(a,b). If d does not divide c, then the linear Diophantine equation ax+by=c has no solution.

I'll have to take your word on that one.

Rum and ------ is up, comrade!